2013-2016 Audi RS7 Front vs Rear Brakes: What Wears First and What to Replace

By Core Brake Parts Tech Team — Circleville, OH warehouse

On a 2013-2016 Audi RS7, the front brakes wear out first, usually by a wide margin. The fronts are the big six-piston, 390 mm wave-design system that does most of the stopping, while the rears are smaller floating calipers with an electronic parking brake motor built in. Plan on replacing front pads and rotors more often, inspect the rears at every front job, and never retract the rear pistons without putting the parking brake into service mode first.

How the RS7 brake system is laid out

The C7 RS7 uses four internally vented discs. At the front, the standard system is a 390 mm rotor with a weight-saving wave-shaped outer edge, clamped by six-piston calipers painted black (red was optional). Audi also offered an optional carbon fiber ceramic system with 420 mm front discs and anthracite gray calipers. That distinction matters more than anything else when you buy parts: steel-rotor pads and carbon ceramic pads are not interchangeable, and aftermarket street performance pads like Hawk's are made for iron rotors only.

The rear axle uses a floating caliper with an electromechanical parking brake. Instead of a cable, a small motor on each rear caliper pushes the piston to hold the car. It is the same electronic parking brake design used across the C7 A6 and A7 platform the RS7 is built on.

Why the front brakes wear first on an RS7

Every car shifts weight forward under braking, which is why manufacturers bias braking effort to the front axle. The RS7 exaggerates that. It is a heavy twin-turbo V8 car, and while its quattro system normally sends 40 percent of drive torque to the front and 60 percent to the rear, none of that changes the physics of stopping: the nose dives, the front tires carry the load, and the front pads and rotors turn most of the car's speed into heat.

That is exactly why Audi fitted six-piston calipers and 390 mm rotors up front and much smaller hardware at the rear. The bigger front brake is built to absorb the work, but it also means the front pads and rotors are consumed faster. On a car driven hard, the fronts can wear through more than one set of pads before the rears need attention. On a gently driven car the gap narrows, but the fronts still go first.

One exception is worth knowing: if the rear pads are wearing close to the same rate as the fronts, look for a sticking rear caliper or a parking brake that is not fully releasing. The electronic parking brake motor sits right on the rear caliper, and a fault there can hold the pads lightly against the rotor.

Symptoms: which end needs attention

• Brake pad warning light: The RS7 uses electronic wear sensors. When the dash warns you, check which axle triggered it, and replace the sensor along with the pads on that axle.
• Steering wheel shake under braking: Almost always a front rotor issue, from uneven pad deposits or thickness variation on the 390 mm discs.
• Grinding from the front: Pads worn to the backing plate. Stop driving it hard; you are now cutting into the rotor.
• Parking brake fault message or a whine from the rear: Points at the rear caliper motor or a botched service-mode procedure from a previous brake job.
• Rear pads worn unevenly side to side: Suspect a sticking caliper slide or a parking brake that is not fully releasing on one side.

To check pad thickness, look through the wheel spokes at the outer pad on each caliper. Compare front to rear and left to right. Large differences left to right on the same axle point to a hardware or caliper problem, not normal wear.

Replacing the front brakes

For a steel-rotor RS7, the front job is pads, rotors, wear sensor, and hardware. The six-piston fixed caliper does not slide, so the pads come out once the retaining hardware is removed, and the pistons are pressed back evenly. Because the 390 mm rotors are large, most owners replace them rather than resurface them when they are worn, scored, or causing vibration.

For a quiet, low-dust street pad on iron rotors, the Hawk Performance Ceramic front brake pad set (HB731Z.620) is one option. Hawk's own application list includes the RS7, and Hawk states its compounds are not compatible with carbon ceramic rotors. Check the fitment on the product page against your car before ordering. You can compare other options in our brake pad collection, our ceramic brake pads, and our replacement brake rotors.

If your car has the carbon ceramic option (gray calipers, 420 mm discs), do not install steel-rotor pads. That system uses its own pads and discs.

Replacing the rear brakes: the electronic parking brake step

The rear job is simple mechanically but has one step that catches people out. The rear caliper pistons are driven by the parking brake motor, so you must use a scan tool to put the system into pad-change mode before you touch them. Ross-Tech's procedure for this platform is: connect a battery charger, cycle the parking brake on and then off, go to the parking brake module, open Basic Settings, and run "Start lining change mode." The calipers then open, and the pistons can be pushed back with a hand tool.

After the new pads are in, run "End lining change mode" the same way so the motors re-adjust. Ross-Tech is blunt about the risk: do not run these settings while the brakes are apart, follow the steps exactly, and scan the car for existing faults first. It also notes reports of repair shops damaging the electronic parking brake while doing rear brakes. Forcing the pistons back without service mode is the classic way to ruin a rear caliper motor.

Rear parts are pads, rotors if worn below the minimum thickness cast into the rotor, and a wear sensor if your axle has one. Our brake parts catalog covers the rear side as well.

What to replace at the same time

• Wear sensors: Once the pad has worn into them they are finished. Replace them with the pads.
• Caliper hardware: Anti-rattle springs and clips on the front, slide pins and boots on the rear. See our brake hardware kits.
• Rotors: New pads on worn or glazed rotors will not bed in properly and often bring the vibration back.
• Brake fluid: Audi schedules brake fluid service by time, not just mileage. If the car is due, a brake job is a good time to flush it with the fluid type printed on the reservoir cap or in the owner's manual.
• Bolts: Torque caliper and bracket bolts to the value in the factory service manual; some fasteners on this platform are meant to be replaced, not reused.

How hard is the job?

The front brakes are a moderate DIY job for someone with a torque wrench, jack stands, and a caliper piston tool. The parts are large and heavy, and the six-piston caliper takes care to reset evenly. The rear brakes are easy mechanically but require a scan tool that can operate the electronic parking brake. Without one, leave the rear job to a shop that has the right software. Either way, bed in new pads with a series of moderate stops before any hard driving.

Frequently Asked Questions

Should I replace front and rear brakes on my RS7 at the same time?

Not necessarily. The fronts usually need replacement first. Measure the rear pads and rotors when you do the fronts; if they are close to their limit, doing both saves a second visit.

How do I know if my RS7 has carbon ceramic brakes?

The optional carbon fiber ceramic system uses 420 mm front discs with anthracite gray calipers. The standard steel system uses 390 mm wave-design discs with black (or optional red) six-piston calipers. Check before ordering, because the pads are not interchangeable.

Can I push the rear caliper pistons back with a C-clamp?

Not until the parking brake is in pad-change mode. The rear calipers have an electronic parking brake motor. Put the system into service mode with a scan tool first, then push the pistons back. Skipping that step can damage the motor.

Why are my rear pads wearing as fast as my fronts?

That is not normal on this car. Check for a sticking rear caliper slide, a parking brake that is not fully releasing, or a leftover fault from a previous rear brake job.

Do I need to replace the wear sensor with new pads?

Yes, if the old pads wore down far enough to trigger the warning. A worn-through sensor will keep the light on even with new pads installed.

Sources

1. Supercars.net - 2013 Audi RS 7 Sportback - 390 mm wave-design front discs, six-piston calipers, 420 mm carbon ceramic option, 40/60 quattro torque split
2. Hawk Performance - HB731Z.620 PC street pads - RS7 application, front fitment, not compatible with carbon ceramic rotors
3. Ross-Tech Wiki - Audi A6 (4G/4H) Parking Brake - rear pad-change (lining change) mode procedure and warnings for the C7 electronic parking brake